“When we talk about this issue, lets consider electric vehicles used in the United States using the average U.S. grid mix,” said Jarod Kelly, principal energy systems analyst at the Argonne National Laboratory, where he examines energy and transportation systems through an environmental lens.
Kelly gave a March 3 presentation of the research tool developed to examine the full impacts of producing and operating fossil fuel-burning transportation and electric transportation.
By comparing similar vehicles, considering the various approaches to generating electricity in the United States, “the electric vehicle significantly outperforms the gasoline vehicle from a greenhouse gas perspective,” said Kelly.
When looking at different fuel types, electricity generated from coal is still an improvement when considering greenhouse gas emissions compared to a gas-powered car, as is the case with electricity generated from natural gas.
However, as many careful observers of the evolution of EVs have noted, emissions is not the only metric to consider when examining the impacts of cars.
“There’s a thing I keep getting asked because of the work that I do, which is, 'Which is better for the environment, a gasoline car or this new electric vehicle? Is an electric vehicle actually better for the environment?'” said Kelly, summarizing a common line of questioning he hears.
“And, because I’m an analyst, my answer to that is wholly unsatisfying to the people that ask it,” he continued. “Because it’s always, well, it depends.”
The definitive answer to this question hinges on the word “better.”
“When we talk about better from an environmental perspective, are we talking about resource depletion? Are we talking about greenhouse gas emissions? Are we talking about other particulate air pollution?” Kelly pondered.
The Argonne National Laboratory developed a research tool to examine these questions. It’s known as the Greenhouse Gases, Regulated Emissions and Energy Use in Technologies (GREET) model. The process analyzes the entire cycle of the fuel and vehicle, from “well-to-wheels,” said Kelly. The model is used by more than 50,000 registered users around the world, and helps to inform public policy.
The model examines the entire fuel cycle — which includes all stages of energy production — from the extraction of resources from the earth, to refining, to delivery. It takes into consideration the “vehicle cycle,” which looks at the resources and materials that go into making a car, as well as pollutants that are emitted during its operation. And finally — in the case of EVs — the model examines the development of the large batteries the cars require.
“There’s a lot of different resources,” Kelly remarked, listing off rare metals like lithium and cobalt, which go into electric vehicle batteries.
“As we increase the number of vehicles on the road, that’s going to put a pressure on the extraction of those material resources. So that will influence things,” he added.
A study by the University of Michigan and Ford Motor Co. found that battery-electric vehicles have a “64 percent lower cradle-to-grave life cycle emissions” than internal combustion vehicles.
With state and federal transportation policy seeming to move firmly in the direction of EVs — given goals to cut greenhouse gases and incentivize adoption in the form of an expanded charging network among other moves — EV models could see higher use.
“Collectively, we can spark and scale the transformative change that will create the jobs, build a healthier, more equitable, more prosperous world. We have the technology,” Manish Bapna, president and CEO of the Natural Resources Defense Council, told the National EV Charging Summit in January.
Bapna pointed out that some 2 million electric vehicles are operating on U.S. roads, a number that is only expected to grow.
